linux-mips
[Top] [All Lists]

Re: sparsemem support on MIPS

To: "David VomLehn" <dvomlehn@cisco.com>
Subject: Re: sparsemem support on MIPS
From: "Jon Fraser" <jfraser@broadcom.com>
Date: Thu, 19 Aug 2010 19:19:45 -0400
Cc: jfraser@broadcom.com, "naveen yadav" <yad.naveen@gmail.com>, "Ralf Baechle" <ralf@linux-mips.org>, "linux-mips@linux-mips.org" <linux-mips@linux-mips.org>, "sshtylyov@mvista.com" <sshtylyov@mvista.com>, "Michael Sundius" <msundius@cisco.com>
In-reply-to: <20100819230613.GA10992@dvomlehn-lnx2.corp.sa.net>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <AANLkTinURQyZgp7bzogjYGzLc5-CyDRGyGo9Hz=pUFFF@mail.gmail.com> <20100819230613.GA10992@dvomlehn-lnx2.corp.sa.net>
Reply-to: jfraser@broadcom.com
Sender: linux-mips-bounce@linux-mips.org
On Thu, 2010-08-19 at 16:06 -0700, David VomLehn wrote:
> On Thu, Aug 19, 2010 at 09:04:21PM +0530, naveen yadav wrote:
> > 
> >  Dear all,
> > 
> > I build MIPS 32 with sparsemem support to take care of holes in
> > physical memory, this conserve memory but put overhead to speed
> > because of pointer redirection in pfn_to_page().
> > 
> > To prevent this conversion I tried to use
> > CONFIG_SPARSEMEM_VMEMMAP_ENABLE on MIPS 32 but kernel build fails
> > becauase most of the supported functions related to vmemmap are
> > supported for 64 bit architectures only.
> > 
> > I wish to compare memory and speed result with / without
> > CONFIG_SPARSEMEM_VMEMMAP_ENABLE in MIPS 32. I need your comment in it
> > ?
> 
> We use sparse memory and submitted a patch some while ago to add support,
> but it died for lack of interest. The patch was relative to a kernel
> from several released ago; I don't know whether it would apply to
> the tip. I can see if I track it down.


I keep thinking we should have a git tree for highmem 'experimental'
changes.  Some of us are shipping highmem, discontiguous memory systems
in high volume.

--jfraser



<Prev in Thread] Current Thread [Next in Thread>